From Picasso to Van Gogh, centuries-old paintings have been targeted by environmentalists as a way of drawing attention to their cause.

The latest artwork to be targeted? Johannes Vermeer's famous piece, Girl with a Pearl Earring. 

One activist has tried to glue his head to the protective glass covering of the masterpiece while a second activist poured a can of tomato soup over him.

So what is going on? Who is behind the protests, what do they want, and who is funding them?

Wait, which artworks have been targeted?

Protesting at a gallery is nothing new, but there's been quite a few demonstrations just this year alone at exhibitions around the world.

In July, climate activists glued themselves to Sandro Botticelli's Primavera at Galleria Degli Uffizi in Florence.

In May, a man was arrested and placed in psychiatric care after he smeared the Mona Lisa with cake at The Louve in Paris.

Closer to home, two protesters were arrested in Melbourne earlier this month after gluing themselves to the protective covering of a Picasso print at the National Gallery of Victoria (NGV).

Recently, protesters at London's National Gallery threw tomato soup on Vincent Van Gogh's Sunflowers.

Days later, liquefied mashed potatoes were thrown on Claude Monet's Les Meules (Haystacks) in Germany.

Now, the Girl with a Pearl Earring by Johannes Vermeer is the latest masterpiece to be targeted in the Netherlands.

None of these artworks have been damaged, but the protests have grabbed global attention.

Are these members of the same group?

Not always.

The demonstration in Florence was done by members of Ultima Generazione (Last Generation) while a similar group, Letzte Generation, claimed responsibility for the Monet stunt in Germany.

Extinction Rebellion claimed responsibility for the protest at the NGV in Australia.

But Just Stop Oil has taken responsibility for the Van Gogh in London.

Right now it's unclear if the demonstration on the Girl with a Pearl Earring is also from Just Stop Oil.

In a video shared online, two men take off their jackets to reveal their tee-shirts which read "just stop oil", but Just Stop Oil hasn't posted about this latest demonstration on their official social media pages.

Who are Just Stop Oil? Who is funding them?

The organisation describes themselves as "a coalition of groups working together to ensure the government commits to ending all new licenses and consents for the exploration, development and production of fossil fuels in the UK."

While Just Stop Oil receives donations from the public, they say most of their funding comes from the Climate Emergency Fund — an American network set up before the pandemic to finance climate activism.

It began with a grant from founding donor and philanthropist Aileen Getty, the daughter of billionaire American oil magnate J. Paul Getty, who was once considered the richest man in the world.

"I personally have no direct ties to the groups in London," Aileen told ABC Radio National.

She says she funds climate activism because "we are facing a widespread climate disaster."

"If you accept that premise, then civil disobedience does not seem crazy and extreme. The climate emergency requires an all-in approach. We need to be pushing on all the levers of today."

Why art? And why these artworks in particular?

When climate campaigners Phoebe Plummer and Anna Holland threw soup on Vincent Van Gogh's Sunflowers, their protest made international headlines.

Holland told ABC Radio National that targeting paintings as a way of drawing attention to their cause "marks an escalation in Just Stop Oil's tactics."

Just Stop Oil don't just stop at throwing soup on centuries-old paintings, though.

They also stage traffic protests, spray-painted a luxury car dealership with their orange branding, and have thrown cakes on King Charles's wax figure at London's Madame Tussauds.

"We will do whatever is non-violently necessary until the government issues a meaningful statement that they will immediately halt all new fossil fuel licenses," Holland told ABC Radio National.